You see, the main charm of Pokémon is its marketability.
For example, let's say Edward is a sucker for Inuyasha, and Joey is more of a poké-dude.
If Ed buys a Kilala backpack, he won't need any more of them because Kilala stands out to him more in the cartoon, and Ed is probably a furfag.
But if Joey buys a Marshadow plush, he'll want to buy a Mew, then a Darkrai, then a Jirachi and so forth until his mom refuses to have pretty much anything to do with Pokémon.